


The GONERS

by Dimensionalbox (Eximplode)



Category: Undertale (Video Game)
Genre: Body Horror, Character Death, Gen, General Disturbing Themes, Sans is main POV character, bad language
Language: English
Status: In-Progress
Published: 2016-03-19
Updated: 2016-03-19
Packaged: 2018-05-27 16:35:57
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 3
Words: 11,550
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6291973
Author URL: https://archiveofourown.org/users/Eximplode/pseuds/Dimensionalbox
Summary: <blockquote class="userstuff">
              <p>Travel through time. Make the old young. Make the dead walk. Determination isn't just a hell of a drug, it's practically a miracle... but how far will one monster's curiosity push its limits?</p><p>Relationships turn sour. Experiments go wrong - or worse, go right. The past is dug up, and unwelcome truths are revealed. And when everything spirals violently out of control, two skeletons are left behind, rebuilding their lives in a shattered world that no longer remembers them or the man they once called their father.</p><p>Based on the "Goner Theory" of W.D. Gaster's disappearance, this story follows the events surrounding the collapse of the Dead Timeline - a catastrophe that sets in motion some of the key events of Undertale, and brings about some of the oddities in the world, including the mysterious Gaster Followers or GONERS, the secret lab, and more.</p>
            </blockquote>





	1. The First

Entry Number ██  
  
Today, I, Wingding Gaster, am bestowed the title of Royal Scientist.  
  
The CORE that powers the whole Underground, converting thermal and magical energy from deep in the earth into electricity… it was my life’s work. My only wish was to provide comfort, safety, and warmth; to make our exile down here a little more bearable.  
  
But when the humans took the lives of the king’s children, they took away our foolish hopes, our dreams of reconciliation. And although things like compassion and kindness come all too easily to monsters, being built into the very nature of our SOULs... as Royal Scientist, it is time to put such feelings aside. With all the resources, materials, and arcane knowledge now at my fingertips, it is both my duty and my honor to assist all of monsterkind in their time of need.  
  
Today, the Kingdom prepares for war. And I will commence my next experiments as per the King’s orders... I will create the weapons we need to reclaim the surface world, and take back what was taken from us. Our soldiers will marvel at their beauty and simplicity, and our enemies will learn to fear them as they fear death itself.  
  
May the Angel above watch over us always.  
  
  
\-----------  
  
Years later…  
  
\-----------  
  
  
It was hard to forget someone like Dr. W.D. Gaster.  
  
The man was practically a legend in his own lifetime; his name spoken only in hushed whispers, following a quick glance over each shoulder. Gaster, the man who designed the CORE. The man who brought light to the whole Underground. The man hand-picked by King Asgore to unlock the power of the SOUL. They say he can find a single discrepancy in a sheet of data just by glancing at it. That he can see the guilt written on your soul if you fudge your results to meet a deadline. That if you even _think_ about slacking off, he’ll come out of the shadows, all seven feet of him, broad-shouldered and thin as a rail... and just _stand there_ until you get back to work.  
  
He moved like a shadow through the corridors, his huge strides barely making a sound, and he never spoke a word unless he had to. All it took was a glance in someone’s direction, and they’d tell him what was on schedule and what was past due, which tests had succeeded and which had failed. He’d hold out one of his bone-white hands, and they’d give him a neat stack of printouts, or a hard drive, or a sample of chemicals for his personal analysis and approval.  
  
Under his careful supervision, the Hotland Laboratory Complex was like a show dog in peak condition; the moment things got out of hand, all it took was a look, or a snap of his fingers, and it would obediently come to heel. But just like a pet needed a master to give commands, it also needed someone to throw it a bone every now and then, which was why every twice-daily inspection was accompanied by the rhythmic footsteps of Gaster’s assistant, and the occasional stifled laugh.  
  
“c’mon matchstick, i know the boss is really _turning up the heat_ , but don’t _burn_ yourself out over there. i mean, you’ve gotta keep a _cool_ head...”  
  
“eyeris? wow, haven’t _seen_ you around for a while, you sure are a _sight_ for _sore eyes._ ”  
  
“hey gary! how about that birthday next week? can’t wait to turn up the _meow-_ sic and get the _paw-_ ty started, if you _cat_ -ch my drift.”  
  
“ah, cheddars, my man, my main monster, can i just say you’re looking _grate_ today.”  
  
A tiny white rat monster, seated atop a chair that towered over the short, grinning skeleton standing next to him, sighed heavily and adjusted his enormous glasses.  
  
“Thankyou, Sans. And it’s _Doctor_ Cheddars.”  
  
“hey, woah, cheddars, i’m not here to _grill_ you. just wondering if everything’s going _gouda_.” Sans continued, putting his hands in the pockets of his lab coat and rocking back and forth on his heels.  
  
Dr. Cheddars squinted his pink eyes in annoyance, but kept his gaze firmly on the computer screen in front of him, both paws typing furiously.  
  
“i mean, i know my jokes are _cheesy_ , but you wouldn’t _brie_ -lieve how much work i put into these puns. dr. g’s already working me so hard these days, i feel like i’m about to...” Sans’ ever-present grin widened even further. “... _crack_ -er under the pressure.”  
  
A pair of tiny fists slammed onto the keyboard. Nobody turned at the sound, but instead froze in place, fear in their eyes and goosebumps crawling up their backs, as Dr. Gaster cleared his throat pointedly.  
  
“Is there a problem, Doctor Cheddars… ?”  
  
Looking up at the looming figure, with white pupils like pinpricks of light in dark sockets, millions of years of survival instincts were screaming inside poor Dr. Cheddars’ brain, telling him to run. But the imminent threat of losing his job proved even stronger; and that left him frozen in place, stuttering helplessly as he tried to explain.  
  
“I… I, ahhh, that is to say, your assistant was… your assistant… was...”  
  
“Doctor Cheddars...”  
  
The temperature in the room dropped by a few more degrees. Attracting Dr. Gaster’s attention in such a way was already tempting fate, but making him repeat himself was like walking through a lion’s den in a suit made of raw steak.  
  
“Is there… a problem?”  
  
“don’t worry about it dr. g, that was my bad.” Sans said, casually reaching up and patting the Royal Scientist on the back. “just took things a little too far. next time i’ll be sure to think of something _feta_ to do.”  
  
“AHAHAHA! HA!” Dr. Cheddars forced a laugh, then quickly scrambled to find more words to fill the sudden, yawning silence. “Yes, see, there’s no problem here, Dr. Gaster! No problem at all! Just some jokes between friends, haha, Sans’ jokes really… crack... er... me up… ha...“  
  
“trying to steal my lines now, cheddars?” There were more than a few suppressed giggles from the back of the room as Sans shrugged. “eh, don’t worry about it. i’ll let you keep that one, on the _mouse_.”  
  
And that was all it took to lift the mood; by the time Gaster turned to leave, handing off the papers he’d gathered to his faithful assistant, everyone was finishing up the day’s work with a smile on their face. Feeling satisfied in a job well done, Sans followed close behind him, putting together his right thumb and forefinger in an ‘OK’ sign, and pulling them apart to reveal a small, glowing portal.  
  
“these can be filed, these need proof-reading…” Sans muttered to himself, adjusting the angle, trajectory and location of the miniature hole in space-time with a flick of his wrist. “...aaaaand these go in the big pile on your desk.”  
  
Pushing the last of the papers through and dismissing the portal as easily as it appeared, Sans realized he was falling behind, and doubled his pace to catch up to the taller monster.  
  
“so, the usual, then?”  
  
“Hm… ?”  
  
Still walking with his hands behind his back, Gaster’s expression was unreadable to most. But as Sans gave a deliberately exaggerated sigh, reached into his lab coat, and pulled out a folded takeout menu, he saw what might have been a ghost of a smile.  
  
“the usual order?” Sans smirked, tapping the menu against Gaster’s coat, and unfolding it like a greasy road map. “it’s tuesday. free eggroll with an entree from yaki tako’s lucky wok. i’m just asking, ‘cause last week you got szechuan snails, and you know how it made you-”  
  
“Mr. Sans! Excuse me- Mr. Sans!”  
  
Scrambling to hide the menu like a dirty secret, Sans didn’t even look up to see who was speaking until they were right in front of him, wringing their hands nervously and tapping their clawed feet on the tiled floor.  
  
“c’mon, alphys…. i told you before, it’s just ‘sans’.”  
  
“B-b-but you’re Dr. Gaster’s assistant! If… if I addressed you so casually… I mean, Dr. Gaster, y-y-you know he wouldn’t… n-not when he might be… ”  
  
Sans couldn’t help but feel sorry for her. Alphys was a prodigy; fast-tracked through high school and college, she’d been signed on as a lab technician while the ink on her degree was still wet, and was already working towards her doctorate. But even after being around him for months, she was still so nervous and weirdly sweaty around Gaster that even the thought of him overhearing had her quivering like a Moldsmal.  
  
“okay, okay, mr. sans it is.” He conceded, patted her reassuringly on the shoulder. “and it’s pretty obvious something’s bothering you. so spill.”  
  
“W-well… you know that thing with the f-flowers I was... s-s-supposed to be doing? Well I... I...”  
  
“you need a deadline extension?”  
  
“I’m so sorry!” Alphys squeaked, covering her face as it flushed bright red. “I messed up! I really messed up! I-I-I’ve just got this personal project, but it’s kind of really a big secret, and I really don’t want anyone to see it, or know about it, and I really shouldn’t be talking about it right now but I can’t help it I’m so sorry I promise I’ll make up for it I just-”  
  
“does a week from now sound good?”  
  
“A-a-a… a whole _week!?_ ” she stuttered, her jaw hanging open in shock.  
  
“yeah. shouldn’t be that hard.” Sans said with a wink, clipboard and pencil magically in hand. “why, wanna make it two?”  
  
It was at times like this Sans was thankful he was nothing but bones. The way Alphys was picking him up and squeezing him, stammering countless thankyous and even more apologies the whole time, he would have been in real trouble by the time a certain Doctor noticed he was missing, and doubled back to see what the hold-up was.  
  
“Am I... interrupting something… ?”  
  
With a strangled sound, like the last of the air escaping from a yellow, lizard-shaped balloon, Alphys let go of Sans and was halfway down the hallway by the time he hit the ground. He groaned; this was the downside of being nothing but bones... no padding except his lab coat, his ‘Gravity Makes The World Go Round’ t-shirt, and a pair of ketchup-stained slacks.  
  
“Oh my, it looks like I _dropped in_ just in time?”  
  
Gaster had to hide his mirth behind his hand as Sans got up, rubbing his tailbone - he wasn’t sure which was more painful; the bruised coccyx, or that awful pun.  
  
“Oh come now, Sans.” Gaster said, his shoulders shaking with barely-contained laughter. “Surely you can stand being the _butt_ of the joke, for once?”  
  
“seriously, dad?”  
  
Like flipping a switch, Gaster’s expression transformed from smiling to stern; “Sans... it _is_ technically seven minutes until the end of the work day… ”  
  
“when we’re talking science, then you can be dr. gaster.” Sans shot back, putting his hands in his pockets and heading back towards their shared office. “when you’re making awful jokes, you’re _dad._ end of story.”  
  
“Alright, alright.” Gaster chuckled, waving his hand, his internal switch flipped back to fatherly mode. “I’ll let it slide this time, but only because you made Ms. Alphys very happy with whatever that was.”  
  
“heh, yeah...”  
  
And she’d be even happier if she knew how much you cared, Sans added mentally, opening up a portal and letting the keys to their office and living quarters drop into his palm. Some part of his soul would always be  _pine_ -ing for Snowdin, the place he and Paps grew up in. But he couldn’t deny the convenience of living where he worked; he could sleep, shower, eat breakfast, step out the front door to go check on the soul chromatography results, and sneak back in for a nap during his lunch break.  
  
“I mean, I realize it shouldn’t concern me, Sans...” Gaster said, leaning a little too heavily on the door as he unlocked it and stumbling inside. “I have no doubts about her brilliance, but all that… that much stress… it… it surely can’t be healthy, for someone... so...”  
  
Sans nearly tripped over his own feet as he scrambled to grab the plush, high-backed office chair, but thankfully, he pulled it over just in time for Gaster to collapse into it. The intimidating figure that had been striding confidently around the labs just moments ago had vanished; in its place was a man left frail and weakened, taking off his reading glasses with shaking hands as the exhaustion he’d been fighting finally caught up.  
  
“geeze…” Sans sighed in relief. His phalanges had been gripping the chair so hard during that tense few seconds, they’d nearly ripped holes in the fabric. “speaking of health, it’s a good thing pap has practice today so he can pick up your prescription.”  
  
“Ugh. Green Magic.” Gaster shuddered, a look of blatant disgust on his face as he sunk lower into his seat. “They can dress up that loathsome stuff however they damn well please, but at the end of the day, it still tastes like boiled cabbage water.”  
  
“well that’s nothing a good eggroll won’t fix.” Sans said; the moment he’d fully recovered it was back to business, holding the phone receiver between his skull and his shoulder, and picking up some folders that a mis-fired portal had dumped on top of a potted plant.  
  
“hey. yeah, it’s sans. we’ll take the usual, aaaand… uh… one order of steamed veggies… special tofu, easy on the sauce… you guys got brown rice? you do? okay, yeah. yeah, hotland lab. thanks.”  
  
“Taking care of your dear brother, as well?”  
  
“somebody’s gotta.” Sans replied; having freed the ficus in the corner of the room from its paper prison, he’d headed over to his desk only to find his favorite hoodie waiting for him, cleaned and folded, with a sticky note describing in vivid detail exactly how filthy it was. “i mean, he takes pretty good care of us.”  
  
“That he does. But I’d say you’re doing a _sans_ -sational job yourself.”  
  
“daaaaad...”  
  
“Alright, I’ll admit, that one really was awful.”  
  
Taking off his lab coat and throwing it over the back of his chair, Sans couldn’t help but give the coat a good sniff, filling his nose with the scent of fresh laundry. Good ol’ Paps… if it wasn’t for him, he wouldn’t have anything to wear that wasn’t held together by its own stains.  
  
“But I mean it, Sans. If it weren’t for you-” Gaster stifled a yawn “-this old fool would be nothing but dust by now.”  
  
Sans’ grip on his jacket tightened for just a moment as Gaster gave a long, drawn-out sigh. But he quickly shook his head, snapped himself out of it, sat down, booted up his computer, and just let his mind wander as he made the necessary adjustment to Alphys’ deadline...  
  
“let’s see, experiments, scheduling, and-”  
  
...And of course, as soon as he laid eyes on the words “DT Therapy”, his mind took off running towards the exact thing he didn’t want to think about.  
  
Sans sighed, covering his eye sockets with his hands and falling back in his chair. So many monsters had Fallen Down lately that the lab had started to take them on as experimental test subjects, trying to salvage some glimmer of hope from the epidemic of hopelessness that was sweeping the Underground. Monsters didn’t get sick like humans did; there were no coughs or colds down here. But for creatures whose souls depended on hope as much as kindness and compassion, despair was a potentially fatal illness, slowly chipping away at the soul until it shattered.  
  
He closed his eyes, letting his arms droop by his sides. He was doing everything he could to help; he had a well-stocked armory of jokes, japes, puns and pranks, every one of them a vaccine against melancholy. But the problem was, as much as he loved making people laugh, that was all he could do. He wasn’t the one leading the Underground’s greatest minds; he wasn’t the one who everyone, from the lowliest coffee-making intern to the heads of the other departments in The Capital, depended on for guidance.  
  
No, that was solely the job of Dr. W.D. Gaster. The man whose every word, movement, and action were internally analysed, filtered, and micromanaged, until all that was left was a terrifying, awe-inspiring, living legend. The mask his father wore every day of his life; hiding his clumsiness, his child-like excitability, his tendency to ramble and gesture wildly with his hands… and the pain that even healing magic could barely touch these days. Sans understood why he had to do it, but that didn’t mean he had to like it. Not when that mask rarely smiled, and never, ever laughed...  
  
...What was he supposed to be doing, again… ?  
  
“SLEEPING ON THE JOB!”  
  
Sans practically jumped out of his seat; if anyone knew how to make an entrance, it was Papyrus. Still dressed in his ‘Hotland Cinders’ uniform, despite having a basketball under one arm, a duffel bag under the other, and several plastic bags in each hand, he’d somehow managed to get down several flights of stairs, and an elevator, and open the office door by himself.  
  
“I SHOULD HAVE KNOWN YOU’D BE SLACKING OFF, YOU LAZYBONES! THAT POOR DELIVERY MONSTER WAS WAITING UPSTAIRS FOR NEARLY A FULL MINUTE BEFORE I ARRIVED TO RELIEVE THEM OF THEIR GREASY BURDEN!”  
  
“you know me, bro.” Sans smirked, turning around in his chair and peeking over the backrest. “why work hard when you can be hardly working?”  
  
“UGH… BELIEVE ME, IF MY HANDS WEREN’T ALREADY FULL, I WOULD BE FACEPALMING SO HARD RIGHT NOW.” Papyrus grumbled, letting his brother take two of the takeout bags.  
  
“hey, i got something for you this time, too, since you had to get dad’s thing.” Sans said, as Papyrus gave an excited gasp. “bland, boring, and completely lacking in flavor. just how you like it.”  
  
“NYEH. YOU JUST DON’T APPRECIATE ANYTHING THAT ISN’T DEEP-FRIED AND COVERED IN KETCHUP.” his brother retorted, opening the bag like a precious Gyftmas present to approve its contents, then adding in a stage whisper; “BUT AT LEAST WE CAN EAT AS A FAMILY TONIGHT?”  
  
Papyrus pointed a thumb towards Gaster; he was doing the world’s least convincing impression of being asleep, with a laughably fake snore, but his reasons became obvious as his exaggerated yawn and stretch routine made his younger son’s eyes lit up.  
  
“Oh dear me, I must have drifted off... but is that _Papyrus_ I hear… ?”  
  
“DAD!”  
  
Sans bit into one of the much-anticipated free eggrolls as he watched the scene unfold, like it did practically every day. Papyrus would come home from class, or from practice, and he’d cling to his dad like a little kid after his first day in kindergarten. And Gaster, who really should have stopped humoring Pap years ago, would hug back, give him a pat on the head, and let him babble endlessly about his day with boundless enthusiasm.  
  
“So did your team win?” Gaster inquired, pouring himself some water from the jug on his desk, and dropping one of the glowing green capsules into it.  
  
“WELL, TODAY WAS JUST TRAINING, BUT EVERYONE DID SO WELL IT’S ALMOST LIKE WE DID!”  
  
Truly, this was a tender family moment. Nothing else like it could bring such a genuine smile to your face, and a warm, fuzzy feeling to your soul... but Sans’ eye was burning with Blue Magic, and his grin had just taken on a mischievous edge. As Dr. G’s assistant, it was his job to make sure things stayed on schedule, especially mealtimes...  
  
“OWIE!”  
  
...And as the older brother, it was his job to annoy Papyrus.  
  
“I KNOW THAT WAS YOU, SANS!” Papyrus snapped, his eyes bulging comically as he threw the fortune cookie right back at him. “YOUR EYE IS STILL DOING THAT WEIRD GLOWY THING!”  
  
“you sure, pap?” Sans chuckled, catching it in his palm. “or was it just an un- _fortune_ -ate coincidence?”  
  
“SANS!”  
  
“or maybe just a little mis- _fortune?_ ”

“ARGH!”  
  
“Boys, _please_ … ” Gaster said warningly, slamming down the empty glass and pinching the bridge of his nose. “Act your age... _both_ of you... ”  
  
Papyrus looked at his feet in shame. Sans, if he’d had a tongue, would have stuck it out, but instead settled for folding his arms in frustration. He’d come close a few times, but not a single one of the day’s efforts had gotten an honest-to-god laugh out of Gaster. Even.when the mask came off, he still couldn’t get through to him some days...  
  
“Despite what you may think, _neither_ of you are too old to be sent to your room.” Gaster said haughtily, picking up a pair of chopsticks and his usual box of noodles. “And you know when I say that... I _lo mein_ it.”  
  
“DAAAAAD!”  
  
“oh my _god._ ”  
  
“What’s the matter, not _veggie_ hungry? You’d better start eating before things get _rice_ cold! Oh come on you two, don’t give me that look, I can’t help being on a _roll!_ ”  
  
Gaster had that that big, goofy grin he always got whenever some new discovery excited him. And now he’d ‘discovered’ the reactions of his sons - Papyrus sending _himself_ to his room, storming off with food in hand, and Sans drowning out his regrets with the crunch of a second egg roll - he couldn’t help but laugh uproariously at his own terrible jokes.  
  
Sans cracked a painful grin. It was going to be a long night.


	2. Experiment

**Summary for the Chapter:**

> The start of one experiment derails another, and something rocks the Underground for the first time in centuries.

Entry Number ██  
  
Research so far is proving… challenging.  
  
My efforts so far have succeeded only in uncovering how much we have lost... centuries ago, our vast libraries, filled with arcane knowledge the likes of which I can scarcely imagine, were the envy of the ancient world. It’s no wonder, then, that when the humans declared war, our scholars were often among the first to fall.  
  
The survivors fled as their scrolls and books burned, taking what they could carry... but then they were imprisoned here, and whatever knowledge could have been reclaimed from memory was simply forgotten. With the day-to-day struggle for survival, our culture entered its Dark Age… progress in magical studies and science all but ground to a halt, until we were able to pick over the leftovers of human technology…  
  
But perhaps, therein lies the solution... much like the CORE, maybe the power we need could lie in a marriage between magic and technology. Even if these alchemical blueprints and ancient texts are damaged or incomplete… knowledge can be forgotten, but the truth is never truly gone. And with even the flimsiest of framework, I can build upon it.  
  
  
\-----------  
  
Yea̴rs la̡te̸r…  
  
\-----------  
  
  
Sans pinched the bridge of his nose, noticeably dark rings around his eye sockets.  
  
His pink fluffy slippers weren’t exactly lab-appropriate attire. Neither was his ‘Particle Physics Gives Me A Hadron’ T-Shirt, which he hadn’t dusted off since that infamous Gyftmas Party last year. And he absolutely should not be drinking coffee in the middle of the lab’s new Medical Trial Center, even if one of the interns had been drawn into the gravitational pull of his exhaustion, and was constantly topping up his mug before he even knew he was running low.  
  
Normally, such offenses would earn him a formal write-up for misconduct at best, and a suspension without pay at worst. But he’d stopped caring about _that_ around twelve cups of coffee ago, and looking around, it wasn’t hard to see why.  
  
“Subject DT-005 is registered and… what do you mean on paper in triplicate!? What is this, the dark ages??”  
  
“Can, uh, someone send an intern down to engineering and ask if they can clamp two beds together… ? Please? P-p-preferably now!”  
  
“For the last time, I have a PhD, but I’m not _that_ kind of doctor!”  
  
“Look, just call maintenance, tell them to bring a bucket of whatever gets a slime trail off tiles-”  
  
“ARGH!”  
  
“...and a ‘Wet Floor’ sign. Maybe two or three of them.”  
  
“damn it, g...” Sans murmured to himself, dunking a Spider Donut in the dregs of his mug. “the hell were you thinking… ?”  
  
He knew the answer, of course. Earlier that week, Gaster had been “called away” to work on a “highly time-sensitive project”, the nature of which was “classified”. But before he’d tightly fastened his Royal Scientist mask to make the public announcement, he’d he’d been practically giggling over breakfast, waltzing around the kitchen to some unheard tune, and wishing his sons an all-too-cheery good morning.  
  
“More coffee, Sans?”  
  
“you know it, scylla.”  
  
He gave a somewhat strained smile as the brightly-colored, shrimp-like monster refilled his cup; despite everything, it just seemed wrong to be mad at Gaster. When his dad got really into something, it was like he was suddenly 30 years younger, and filled with so much hyperactive energy that even Sans struggled to keep up sometimes… and cabbage-tasting Green Magic was hardly a substitute for that. Nothing could beat the healing, energizing power of real joy. He couldn’t stay mad at him for that.  
  
Sans flinched as the sound of breaking glass came from somewhere behind him. Nope, he wasn’t going to get mad... but this rate he was going to need something a lot stronger than coffee...  
  
“Hey Sans.”  
  
“hey gary... man, you look like something the _cat_ dragged in.”  
  
“And you look like _death_ warmed over.” He smirked, his paw scratching at the dark patch of fur that seemed to be the equivalent of 5 o’clock shadow, and picking up an overflowing stack of printouts.  
  
Scylla giggled; “He’s right, Sans. Maybe you should lay off the coffee. I’m surprised it doesn’t go right through you.”  
  
Sans shook his head. “man... you two keep it up, i might have to steal your bit for my next stand-up routine. i mean you never know, maybe when i tell it, someone might actually laugh.”  
  
It always did the trick; leave ‘em laughing, and they won’t know what hit ‘em. Sans made a hasty exit while they were distracted, not letting them see the look of exhaustion on his face. He gave a sigh of relief as he finally made it to one of the quieter corners of the room, and sat down on what was probably a very important pile of paperwork; finally, he was alone. Alone with his thoughts. And the pandemonium the Med Lab had become.  
  
“ugh…”  
  
Sans held his head in his hands. Okay, yeah, it did make him feel like the scum of the earth, but maybe he was justified in being just a _little_ bit mad at Gaster. He was always tinkering with something, but god, he just _had_ to pick the _worst possible time_ to sink into full-blown obsession...  
  
His fist slammed down on another pile of paper as he fought to contain his frustration. Everyone was counting on good old Sans to keep the laughs coming, to be a friendly face, to keep their hopes up... some called him the heart of Hotland Labs, but what good was a heart without a brain? The moment Gaster stepped back, the place’s collective IQ had dropped like a stone, and it still showed no signs of stopping. People panicked, panic led to stupid mistakes, those mistakes led to even more panic, and eventually monster had turned against monster.  
  
The place had become a battlefield, and Sans was helpless to choose a side. Medical doctors from the capital were arguing with doctors of chemistry. The technicians were utterly lost, navigating the no-man’s land in between them as they tried to co-ordinate. And the paperwork, _god_ , the paperwork, piling up like snowdrifts and threatening to smother even the poor, comatose patients...  
  
“YOU THERE! Yes, you, Sans! This is a _laboratory_ , not a corner cafe!”  
  
….And just like a real battlefield, there were scavengers waiting to pick over the pieces. Like Dr. Tessall, for example, who proudly enunciated every syllable of ‘laboratory’, and had declared themself de facto leader amidst the anarchy. They were glaring at Sans, their hands on their hips, tapping their foot impatiently… and if they’d had something other than a puzzle cube for a head, the expression on their face would have truly completed the look of a no-nonsense school teacher.  
  
“what?” Sans asked, slipping just as effortlessly into the role of the class clown. A portal dropped the box of Spider Donuts into his hands, and with a look of wide-eyed innocence, he offered one to his colleague. “i brought enough for everybody, didn’t i?”  
  
Tessall’s colored tiles rearranged themselves into an accusatory red ‘X’ as they leaned closer.  
  
“okay, okay, i’m sorry, that was bad even for me.” Sans said, dropping the box through a portal to the office and holding up his hands in surrender. “but i think i speak for everybody when i say we’re all just a _little_ bit stressed right now, doncha think? i mean, you’d be surprised what good a few pastries can do… heh, unless you’re a spider... but the point is-”  
  
“The point is what, exactly?” Tessall stood up straight again, their arms folded. “Do make it snappy, I have a control group to check on.”  
  
“my point… ?” Sans looked back, his eyes like two black holes. He’d had more cups of coffee than he could count, but still not enough to deal with this right now. “my _point_ , dr. tessall, is we haven’t even _started_ testing yet... not that we could, with all this mess... and under your careful supervision, too… ”  
  
Tessall’s tiles scrambled in momentary confusion. “Yes, well… I… ”  
  
“so it’s a good thing, wouldn’t you say… ” Sans continued, his square-toothed grin suddenly looked as threatening as a mouth full of fangs. “that the control group’s not even due to start for another two days... _right_ , dr. tessall?”  
  
“Well… just… do try and keep the workspaces clean, alright? It is for everyone’s safety… “ Tessall said, looking around for a way to escape. “And… with all due respect, Mr. Sans, you may want to re-check the schedule. I do believe an adjustment may have been made.”  
  
They left quickly, leaving Sans frozen in place, his soul feeling like it just hit the floor. An adjustment? _He’d_ been the one making the adjustments... as soon as Alphys asked for that deadline extension, he’d fixed it for her right away. He’d gone straight to the office with Gaster, and he’d fixed it, right there on the system’s schedule, just like she asked...  
  
_...Hadn’t he… ?_  
  
Sans was up and running before he’d even finished his thought, ducking and weaving his way through the chaos of the overcrowded room.  
  
“Sans, wait! Didn’t you want more coffee?”  
  
“Wait, that was _Sans?_ ”  
  
“Holy smokes, look at him go!”  
  
“ _Watch the floor!_ ”  
  
Sans found himself cursing his lab-inappropriate footwear as he slid along the tiles, but it at least gave him enough momentum to kick open the double-doors at the end of the room. If he knew Dr. Tessall - and he knew _everybody_ , he thought, taking a mental note to apologise to the monster whose legs he’d just dived between - they’d be on their way to Alphys right now, demanding to know why the hell the control group was so behind schedule. God, he’d really screwed this up… and of course the only guy with enough authority to step in and prevent the inevitable just had to be _Gaster_.  
  
Rounding the corner and skidding a little on the floor, he threw open a portal, catching his missing, slime-soaked slipper in his hand as he half-ran, half-hopped to the office door. Finally… all he had to do now was get the key. All he had to do was just open a portal, right under where it was on the shelf, and it’d fall right into his hand. Frowning, he tried again; just the key. That was all. Just do that, and everything’s fine. Everything’s just _peachy_.  
  
“oh, _come on!_ ”  
  
Shoving his arm into the portal, Sans scrabbled around blindly for something, _anything_ , resembling a key. Either Gaster was really adamant about not being disturbed this time, or panic had him so tightly in his grip that he’d missed the mark, but it wasn’t like he could help it. Not when he could see the whole damn scene playing out in his head, with Tessell shouting and Alphys bowing her head in shame... she wouldn’t try and explain things, she wouldn’t try and defend herself. She’d just stand there and take the blame, and all the reparations that came with it, all because of _his_ stupid mistake.  
  
Sans sighed; he really hated doing this. But seeing no other choice, he grit his teeth, closed his eyes, and brought the portal up to eye level.  
  
“welp… here goes nothing...”  
  
“Ah, Sans! Right on time, I see!”  
  
Sans pulled his head back in surprise, and immediately regretted it. Sticking his head through a portal was bad enough... the feeling of different parts being in two points in space-time at once made his non-existent skin crawl. But going in and out like that with no time to get his bearings left him staggering backwards, clutching his head as the room swayed back and forth, and suddenly lurching forwards when Gaster grabbed his arm.  
  
“dad, wait-!” Sans started, but he’d already been pulled inside the office.  
  
“Waiting can wait, my boy! We really mustn’t dawdle!” Gaster said; the room was spinning so violently that Sans couldn’t tell what was up or down, but the sound of muted beeping could only mean he was entering his passcode to his private lab.  
  
“dad, seriously, i can’t explain right now but you gotta come with me-”  
  
Gaster just laughed; he seemed to be in a world of his own, stepping behind his son and giving him a gentle push towards the door.  
  
“Oh, what am I saying? Technically it doesn’t matter if we do this today, tomorrow, or even _last week!_ But you know what they say, there’s no time like the present!”  
  
“dad...” Sans shook his head, and pulled his hand back as his father went to grab it again. “dad, look, i really can’t do this right now. i forgot to fix the schedule on tuesday, the whole’s damn med lab’s up shit creek, and alphys is gonna be without a paddle unless-”  
  
“Tuesday? Oh but that’s perfect! Simply _perfect!”_ Gaster chuckled, gently ushering him inside. “Trust me, Sans, this will all make sense once I show you what this machine can do.”  
  
“wait, what? dad, are you even listening-”  
  
Sans squinted and shielded his eyes as the ceiling lights flickered into life. They started at the front of the room and moved towards the back, just like he’d seen dozens of times... but as each set drew closer to the ambiguous shape hidden by a thick cloth, they felt almost theatrical. And like an actor to the stage, Sans was drawn to it, walking all the way across the room in a kind of trance to run his phalanges over the console beside it. Its surface bristled with switches, dials, and colorful buttons of all shapes and sizes; all of unknown purpose, but as tempting as an unguarded bowl of non-licorice Monster Candy.  
  
“Mesmerizing, isn’t it?” Gaster smiled, plucking something from the breast pocket of his lab coat. “To think that such incredible power was at our fingertips this whole time. Waiting for us, mere inches out of reach… if only we’d known sooner.”  
  
Sans watched, tiling his head to see better, and caught sight of an eerie red light between Gaster’s fingers; a tiny glass vial, about the size of a battery for a children’s toy. He pressed it into an equally tiny, strangely heart-shaped slot with a soft ‘click’, and the machine suddenly hummed into life, tubes and wires like veins and arteries, pulsing softly beneath the protective cover.  
  
His curiosity burned. But something else burned stronger, and flared white hot as it remembered the confrontation with Tessell, the terrible state of the DT Trials, and the downright ludicrous levels of caffeine coursing through his system.  
  
“ _listen,_ dr. g.” he said, gritting his teeth. “whatever this thing is, whatever this thing does, we do not. have. _time_ for it.”  
  
“That’s where you’re wrong, Sans.”  
  
With an unsettling look of focus on his face, Gaster pushed his assistant out of the way and stood over the control panel, playing it like a piano virtuoso. He was pushing buttons, pulling levers, and twisting knobs with expert precision, and with every carefully co-ordinated movement, the machine responded. With the sheet slapping in an unseen gale, its light grew brighter and brighter until it was so blinding, its searing glare threatened to bleach Sans’ bones. Its gentle hum grew to such catastrophic proportions that it shook the foundations of the building, knocking books off shelves, shattering glassware, and plunging the rest of the room into darkness as the lights failed.  
  
And somehow, he still heard Gaster’s triumphant shout...  
  
“ _WE HAVE ALL THE TIME IN THE WORLD!_ ”  
  
...Before everything went white.  
  
…  
  
..  
  
.  
  
...What was he supposed to be doing, again…?  
  
“SLEEPING ON THE JOB!”  
  
Sans fell out of his chair in shock; and just as karma would have it, he landed right on his already-bruised tailbone.  
  
“ _SANS!_ ”  
  
Reacting immediately to his brother’s cry of pain, Papyrus dropped the bags of takeout he’d apparently carried down several flights of stairs, and an elevator, and through the office door all by himself. Kneeling by Sans’ side, he cradled him like a soldier would a wounded comrade, worried tears streaming from his eye sockets.  
  
“ARE YOU ALRIGHT!? DID YOU BREAK ANY BONES!? HOW MANY FINGERS AM I HOLDING UP??”  
  
Sans groaned, leaning back dramatically in his brother’s arms. “pap, i… i think something... has a _crack_ …  ”  
  
His brother gasped in horror.  
  
“i think... it’s... my butt...”  
  
Papyrus’ eyes narrowed. It took a moment for realization to set in.  
  
“SANS, OH MY _GOD_.”  
  
It hurt like hell when his brother dropped him, but Sans was laughing so hard that it hardly mattered.  
  
“THAT DOESN’T EVEN MAKE _SENSE!”  
_  
“i’m sorry, pap… ” Sans wheezed, wiping a tear from his eye socket as he got up. “the look on your face was _priceless_.”  
  
“I’M NOT TALKING TO YOU.”  
  
“aw, c’mon, bro, don’t be like that. you know me, i can bounce back from anything once i get ahold of something deep-fried and… covered in… ketchup…”  
  
Sans rubbed his head in momentary confusion - why did it feel like he’d heard that line before?  
  
“UGH…” Papyrus grumbled, picking a few stray takeout boxes off the floor. “BELIEVE ME, IF MY HANDS WEREN’T ALREADY FULL, I WOULD BE FACEPALMING SO HARD RIGHT NOW.”  
  
Huh… there was that weird feeling again...  
  
“WAIT, IS _ALL_ OF THIS FOOD FOR YOU?”  
  
“what?” Sans looked up. “oh, uh, actually that’s one’s for you, pap. bland, boring, and completely lacking in flavor... just how you like it....”  
  
He swallowed dryly, the words turning to ashes in his mouth. This was getting weird... he always made every effort not to repeat his jokes, but he’d _definitely_ said that before. He was almost sure of it.  
  
“WELL MAYBE IF YOU ATE YOUR GREENS TOO, YOU WOULDN’T LOSE HALF YOUR HP FALLING ON THE FLOOR. NYEH.” Papyrus retorted; he looked like he’d be sticking out his tongue, if he’d had one.  
  
“heh... yeah...”  
  
Sans couldn’t muster a counter-insult as he sat down - _very gently_ \- in his chair. He couldn’t remember falling asleep, but there were snippets of a really weird dream still running through his head; one where Gaster was gone, the lab was falling apart, and he’d been drinking so much coffee he was surprised his bones weren’t stained brown.  
  
“OH! SPEAKING OF GREENS, I HAVE DAD’S PRESCRIPTION RIGHT HERE.” Papyrus said, shaking a bottle of glowing green capsules. “I WAS HOPING HE WOULDN’T BE BUSY SO WE COULD EAT AS A FAMILY... BUT YOUR COMPANY IS APPRECIATED AS ALWAYS, DEAR BROTHER!”  
  
“wait.” Sans froze. “you mean he’s not-?”  
  
He turned around, and felt an icy grip on his soul as he saw the empty chair. Gaster had been struggling to keep going since they’d finished their inspection of the DT Extractor. He’d been so exhausted by the time they’d collected the day’s chromatography results that he’d literally collapsed the moment he set foot in the office. He’d been pushing himself so hard lately that he was completely out of Green Magic to counteract his chronic pain. There was no way in hell he could have just got up and walked away.  
  
“SANS… ? ARE YOU SURE YOU’RE OKAY?”  
  
“dad… ”  
  
Sans’ hands shook. The grip tightened, the cold feeling of dread driving itself deeper, and his breath caught in his throat, his pupils like tiny white pinpricks as he teetered on the verge of a panic attack. This wasn’t happening. This wasn’t real. Monsters didn’t just disappear, not unless… unless they...  
  
“...d-... dad was…”  
  
“Dad was what?”  
  
The door to the private lab slid open, and Gaster stepped out as casually as on any Tuesday evening.  
  
“My ears are burning, Sans... or they would be, if I had any- _OOF!_ ”  
  
Gaster seemed taken aback, but the same could be said for anyone if they’d been tackled and nearly knocked to the floor by not one, but two fully-grown skeleton monsters.  
  
“Well... as the chemist said after the explosion, this reaction was somewhat unexpected!” Gaster said with a laugh; he patted Papyrus on the head as usual, but hesitated when he got to his eldest son. “Sans? Are you feeling alright?”  
  
“i, u-uh...” Sans stuttered as he let go. He couldn’t have told a more obvious lie; his soul was still pulsing like crazy, its magic so overworked by panic that it was visibly glowing through his shirt, but he still found himself pulling his jacket closed in embarrassment. “y-yeah. i’m just _peachy_...”  
  
Gaster looked to Papyrus, who seemed just as confused as he was, and then back to his eldest son, who was still mentally struggling with the relentless onslaught of deja vu.  
  
“Was I… absent for very long?”  
  
Sans’ eyes narrowed suddenly in confusion and suspicion; what kind of question was that... ?  
  
There was a long and awkward silence.  
  
“...YOU’RE BOTH ACTING REALLY WEIRD TODAY.” Papyrus said, getting straight to the point as usual. “BUT I’M GOING TO SET THE TABLE FOR DINNER. EVEN TERRIBLE FOOD DESERVES GOOD PRESENTATION!”  
  
“Ah, yes, yes… a very good idea, Papyrus…” Gaster said, quickly extending his hand as Sans wordlessly went to follow him. “Ah, Sans? Could you wait just a moment?”  
  
“alright.”  
  
Sans made sure to hit the button to close the door. He didn’t want Papyrus to hear what he said next, as he turned to face their father.  
  
“so are you gonna explain why you made me think you’d up and turned to dust?”  
  
Gaster looked suitably horrified.  
  
“Turned to-!? Sans, I’m so sorry, I didn’t mean to... I just wasn’t completely sure how things would change following the Reset, I mean, I assumed a few factors might persist from the moments before the machine activated, but I had to go and check the readings-”  
  
“wait wait wait wait…” Sans held up his hands. “what does this have to do with me waking up and you not being here? or how the hell you’re even _walking around_ right now? fifteen minutes ago I had to catch you when you leaned too hard on the door!”  
  
“Does _none_ of this sound familiar at all?” Gaster’s hand covered his mouth; he looked stunned, like this was another reaction he wasn’t expecting. “I mean, I probably should have explained more while I had the chance, but you were very much in a hurry, and doubtlessly angry at me for the state I’d left the Med Lab in, given you described it so colorfully as, and I quote, ‘up shit creek’.”  
  
Sans just stared blankly; not only was the Med Lab nearly a full week away from being operational, but that _really_  didn’t sound like something he’d say in front of his dad.. _._  maybe at the last Gyftmas party after a few too many cups of punch, but...  
  
Gaster laughed nervously; “Great Angel above, you don’t remember _anything_ , do you?”  
  
“remember _what?_ ” Sans asked, more desperate than ever to get a straight answer. “dad, i don’t… can you just explain what the _hell_ is going on?”  
  
Gaster gently put his hands together, just as he always did when he was trying to stay calm. He closed his eyes, he took a deep breath... and despite his efforts, he couldn’t contain himself, bending down to Sans’ level and grabbing him by the shoulders with a huge, excited smile on his face.  
  
“Why, time travel, of course!”


	3. Discovery

**Summary for the Chapter:**

> Discovery. Anger. Betrayal. Secrets, secrets, and more secrets.

Entry Number ██  
  
I’ve done it… by the Angel above, I’ve finally done it! I have achieved what no monster has in thousands of years!  
  
The ancient manuscripts were barely adequate by themselves… even a bare-bones translation took the professors at Capital University’s language department months to prepare. And despite being the Underground’s authority on the subject, it embarrasses me to say that untangling ritual and superstition from genuine incantations and arcane techniques took me even longer. But all those days spent squinting at runes, those late nights deciphering blueprints… all of it has led up to this moment.  
  
It is a well-known fact that raw magic is a monster’s greatest form of self-expression… their personality, their interests, even their species... all of these things play some part in shaping an individual’s ‘bullets’. But this construct, though it is hewn from my own magic in much the same way… when I look upon it, I see not a reflection of myself, but of everything that I strive to be.  
  
Truly, I am in awe of what I have created. But regardless of my feelings... my apprehensions... the integrity of the construct will need to be proved before ‘mass production’ can begin. Intensive testing will commence immediately.  
  
  
\-----------  
  
Y̸ears ̶l҉at͢er…  
  
\-----------

 _“Why, time travel, of course!”_  
  
The words still echoed in Sans’ head like the remnants of a dream. Time was the river in which the universe itself swam; everything within it was immersed in it, intertwined with it, and always, relentlessly moving forwards. To swim against the current, that was time travel in theory… but by doing so, you changed the course. You changed _everything_ . And as for retaining memories of something that had ‘un-happened’... that should be as impossible as taking a cup of water from that river, emptying it, and then taking the _exact same cup of water_ again, right down to the molecule...  
  
Sans pushed aside a piece of paper; apparently his internal analogy had gotten away from him, because he’d somehow covered it in crude doodles of fish. But even _that_ made more sense than what was laid out right in front of him, in frantic, scribbly Wingdings shorthand...  
  
“you know, dad, if you weren’t so serious about science, i’d swear you were pranking me.”  
  
“And why is that?” Gaster said, his feet up on one of the work surfaces, and his hands hard at work with a complicated, pyramid-shaped puzzle toy. “Surprised someone specialized in a _lesser science_ like Arcane Engineering could figure out something so complex?”  
  
“dad…”  
  
“Oh come on, we both know you were thinking it.”  
  
“well, can you blame me for being just a _little_ skeptical? i mean, _look_ at all this stuff.”  
  
Sticking his pencil where his ear should be with a tiny amount of Blue Magic, Sans gestured to the notes covering the chalkboard, written on countless notepads... even going across multiple sheets of paper at once in a long, unbroken trail. To anyone who couldn’t read Dingbats-based languages, it would have seemed like the scribblings of a madman, and to anyone who _could_ , the description still wasn’t that far off.  
  
“it reads like instructions to defuse a bomb with a moustache comb, some safety scissors, and a rubber duck.”  
  
The puzzle clicked a few more times as Gaster rotated it. “Impressive but impractical?”  
  
“more like something that should be impossible, but somehow isn’t.” Sans turned around in his chair. “kinda like the CORE project. nobody actually knew how it worked ‘til it did.”  
  
“You mean until _you_ figured it out.” Gaster chuckled. Having finished the puzzle in record time, he quickly moved on to another, this time a series of complex, interlocking metal rings. “I still remember the look on your face when I walked in... hiding the chalk behind your back, like you’d been caught with your hand in the cookie jar… ”  
  
“well yeah, quantum physics, that stuff just comes naturally when you can do this.” Opening a portal, Sans let the first puzzle fall into his palm, and randomly twisted its various sections as he continued. “it’s just this DT stuff i don’t get... using it as a power source seems pretty ‘out there’, but if these readings are right, if we didn’t already have the CORE we’d sure as hell have one now.”  
  
There was a soft ‘clink’ as Gaster set down the last of the rings atop the neat pile he’d made. He gestured for the freshly-randomized puzzle to be returned to him, and Sans obligingly opened a portal, picking up his pencil again. His dad’s crazy notes were covering some of it, but the printouts still held the same valuable data from the lab’s analysis of the Determination samples.  
  
“i mean, the thaumic density of this stuff must be _insane_ . if DT was physical matter instead of metaphysical, it’d weigh as much as a neutron star. maybe even more, if that’d mean it didn’t just collapse into... into a black hole… ”  
  
Sans stared into the corner of the room. Then his eyes lit up and suddenly he was on his feet, flipping over the double-sided chalkboard, frantically writing equations with his left hand while his right directed his Blue Magic, sketching the shape of an inverted cone with a whirlwind of chalk dust.  
  
Gaster put down his puzzle and approached slowly, like the sound of his footsteps might somehow break the spell. “So the power of DT is so concentrated, it creates a distortion in space-time?”  
  
“nope.” Sans said, grinning broadly as he drew a heart-shaped human soul at the bottom of the cone. “DT doesn’t _just_ cause a distortion...” He circled it two or three times for emphasis. “...wherever it’s concentrated enough, it creates a _fixed point_ in space-time.”  
  
“Great Angel above, _that’s how they do it!_ ” Gaster didn’t even try to contain himself, clapping his hands excitedly as he watched Sans make the numbers dance, his equations giving mathematical proof of what he’d just explained. “ _That’s_ how human souls persist after death! That’s how SAVE and LOAD work! _It’s like pushing a pin through the fabric of the universe!_ ”  
  
“and it’s also why the DT sample is still over there.” Sans said, gesturing towards the machine with his thumb. “fixed points in space-time tend to stay where you put ‘em.”  
  
“ _That’s_ why the Reset Machine is still functional!” Gaster groaned, slapping himself on the forehead. “Performing a Reset should have undone nearly a full week of work on the blasted thing, and I never even _questioned_ it… Angel Above, you really must think I’m a fool.”  
  
Sans shrugged casually. “nah, you’re an arcane engineer. but that’s basically the same thing, right?”  
  
...And he quickly found himself with deja vu again, quickly pulling over a chair as Gaster collapsed into it, wheezing with laughter. Feeling dizzy, he leaned on a nearby countertop for support; his magic had gotten a real workout today, and he was hours late for dinner, but… Sans shook his head. He’d lost his train of thought, but the thing he’d just noticed sitting next to his hand had started it on a different track entirely.  
  
“wow, uh, i take that back. you’re really sharp today, huh?”  
  
“Sorry, what was that?” Gaster was still laughing as he turned in his chair. Then he saw the completely solved pyramid puzzle that Sans was holding, and his good mood suddenly screeched to an immediate halt. “O-oh... yes, I… I suppose I am…”  
  
Sans looked at him skeptically, which seemed to make him even more nervous.  
  
“Well, you know what they say! Nothing gets the soul sparking like a scientific discovery, except maybe a good eggroll!” He got up quickly, moving behind Sans and gently pushing him towards the door. “Come on then, don’t just stand there! Poor Papyrus must be wasting away, waiting for us, and goodness knows he needs some meat on his bones as it is! Ha!”  
  
Putting down the puzzle, Sans silently led the way out of the private lab and into their living quarters. Dad couldn’t have made it more obvious he was hiding something, but he figured he’d have a much better chance of figuring out what the hell he’d just stumbled upon on a full tank of food magic.  
  
“AH, THERE YOU ARE! I HAD A FEELING YOU’D BE HUNGRY SOON, SO I ALREADY ENLISTED THE HELP OF OUR FAITHFUL MICROWAVE!”  
  
He sat down at the table, picking up an eggroll from the serving dish in the center, and bit into it purposefully as he went over things in his head. Dad loved his puzzle toys, and that was a fact… Papyrus always gave him a new one for every birthday and Gyftmas...  
  
“I MEAN, NOBODY LIKES CHINESE FOOD WHEN IT’S _RICE_ COLD! NYEH HEH HEH!”  
  
Gaster sat across from him, noticeably avoiding eye contact, and even more noticeably twirling his chopsticks in his hand until Papyrus finally set down a plate of noodles and sesame snails. He used those puzzles almost as much as the black ‘spinner’ ring Sans himself bought him a few years ago - a low-key way to quell his fidgety hands while he patrolled the lab - but there was something weird about it today.  
  
“Thankyou, Papyrus… you really are - heh - on a _roll_ today…” Gaster said, smiling half-heartedly.  
  
Sans frowned. Even as deja vu reared its head, and a plate of delicious, greasy food was finally put in front of him, he needed to stay focused. But maybe he was overthinking things? Maybe not being able to take a compliment just ran in the family. Or maybe he was just hungry. The food did smell _really good_ .  
  
“IT’S... NICE TO EAT AS A FAMILY.” Papyrus said hesitantly; he seemed mildly upset by the lack of cheerful conversation and family bonding going on. “I KNOW I DON’T REALLY UNDERSTAND YOUR SCIENCE-Y STUFF…”  
  
Gaster gripped his chopsticks a little tighter, his fingers twitching. No, there it was again... that same weirdly frantic energy that went beyond mere excitement. Even as he picked up his cup of water, they made a rhythmic tap-tap-tap against the glass...  
  
“BUT IT’S NICE TO SEE YOU BOTH SO HAPPY ABOUT IT?”  
  
Sans almost spat out his lo mein - that was it!  
  
“I… THOUGHT I HEARD LAUGHTER THROUGH THE DOOR, WHEN I CAME BY TO CHECK ON YOU.”  
  
Dad’s hands were always moving. They moved in ways he didn’t even notice, and when it came to his puzzle toys, actually _solving_ them was a low priority compared to scratching that itch!  
  
“IT… SOUNDED LIKE YOU WERE... HAVING FUN… ?”  
  
But just now, he’d solved two different puzzles in a matter of minutes! He’d even solved one _twice!_ It was a feat not even Pap himself could have managed… and there was the water, too, which could only mean-  
  
“SANS! I CAN’T BELIEVE I’M SAYING THIS, BUT DO SLOW DOWN A LITTLE!”  
  
“sorry.” Sans murmured, wiping sauce off his face. Either he was even hungrier than he’d thought, or Gaster wasn’t the only one with hands that moved by themselves. “i should get back to work soon, so i guess you could say i’m _determined_ to finish eating.”  
  
The pun was actually a slip-up; there was no way Papyrus could have got the joke. But a certain someone sitting right across from him _did_ , and nearly choked on his own noodles before quickly excusing himself from the table.  
  
“DAD!? SANS-! SANS, WHAT’S GOING ON!?”  
  
Sans had a hunch, but there was only one way to find out; he chased after him, running down the hallway, and stuck his foot in the door to the private lab just before it could lock him out. Gaster didn’t try to stop him; he just stood there, his hands neatly clasped behind his back, the silence broken only by the little grinding noises of him twisting his spinner ring.  
  
“well?” Sans asked, expectantly. “you heard what pap said. what _is_ going on?”  
  
Gaster sighed.  “I know what you are thinking, Sans, and it does not concern you.”  
  
“if it’s about _my dad_ , then it sure as hell _does_ concern me!” Sans snapped. “you’ve been completely wired since this whole time travel thing kicked off, and yeah, don’t get me wrong, that’s _great_ -” Opening a portal, a bottle of glowing green pills fell into his hand. “- but you also haven’t touched your prescription _all night_ .”  
  
Gaster’s shoulders slumped. “It’s _nothing_ , Sans.”  
  
“nothing, huh?” Another portal opened, and the pills disappeared into it. “well whatever ‘nothing’ it is that’s in your system, it hasn’t fixed how you can’t lie worth squat.” Sans glared at Gaster, folding his arms defiantly. “paps gets that from you.”  
  
Another exasperated sigh. “Even if I told you, you would not understand.”  
  
“ _i_ wouldn’t understand?” He picked up one of the rolled-up blueprints on the desk, and waved it at his father. “just like _you_ didn’t understand how the machine _you built_ actually _works?_ ”  
  
Gaster whipped around suddenly, his eyes flaring like two hot coals. “That is _NOT_ what I meant and YOU KNOW IT, _BOY!_ ”  
  
Sans recoiled in shock, stumbling backwards; he’d never seen his dad use _any_ magic before, nevermind Orange Magic, one of the rarest colors on the emotional spectrum. How many more secrets was he keeping from him!?  
  
“I… I did what was required to test the machine.” Gaster continued, putting a hand to his forehead as he straightened up; he looked confused, like the sudden surge of Bravery was a surprise to him, too. “I suppose some... side-effects were to be expected... but they should pass, in time… ”  
  
“wait... side-effects of… ?”  
  
For just a brief moment, Gaster glanced towards the corner of the room, where the heart of the Reset Machine gave off a soft, red glow... and that was it. That was enough for Sans’ mind to finally add everything together. And he threw the blueprints he was holding onto the ground as he finally snapped.  
  
“ _are you kidding me, dad!?”_  
  
“No. I am not.” Gaster said seriously. Sans turned towards the workbench to frantically look over the rest of the notes; there had to be something, somewhere, that would tell him this wasn’t real, that this wasn’t really happening… but his father kept talking.  
  
“The extractor has been outputting DT of 99.8% purity or higher for the past two weeks… three, if you count the time lost after activating the Reset Machine… and even those samples would have been merely disposed of in the CORE’s incinerator, had I not-  
  
“and your first thought was using it on _yourself?_ ” Sans’s fist crushed a fistful of papers that proved the exact opposite of what he’d been hoping for. It was right there, in black and white, and he still couldn’t believe it. _“_ for this… _resonance_ thing?”  
  
“I did what was required to test the machine.” Gaster repeated himself, as patient as the grave. “The concentrated DT sample that powers it cannot function alone... my calculations determined that an infusion of 0.01% DT would be adequate to allow operation of-”  
  
“and you did this _before_ we tested it… ?” Sans dropped the papers, falling back into the chair behind him in shock. “before we’d even tested it on monsters that’ve _fallen down!?_ ”  
  
The irritation was evident in Gaster’s voice: “I did. What was required. To test. The machine.”  
  
“ _you gave yourself a dangerous, untested, experimental drug!_ ” Sans shouted, standing up in the chair, turning it around with Blue Magic to look Gaster in the eye. “a drug that _you stole_ from the labs! a drug that could have _killed you!_ because you just _had_ to be the genius royal scientist! you just _had_ to mess with shit you didn’t understand! and your stupid skull’s so far up your own _fucking_ pelvic bone that you wouldn’t even _think_ of asking for _my help!_ ”  
  
Sans clutched his pounding head as he sank back into the chair. His breath came in short spurts. His magic was surging, lighting up his soul like a beacon, making his left eye burn with cold fire. Anger, fear, and betrayal crashed down onto him in waves, dragging up unwelcome memories from the depths. Memories of an empty chair... and thinking, if just for a brief moment, that it would _stay_ empty...  
  
_If it weren’t for you_ , _this old fool would be nothing but dust by now._  
  
He didn’t realize he was sobbing until he felt his father’s arms around him.  
  
“Sans, listen to me... the moment I discovered the capabilities of the human soul, you were the first thing on my mind. I thought of those books and comics you read... how you pursued your degree in Theoretical Physics with the intent of making them real... and I imagined the look of excitement and joy on your face when I told you about this experiment-”  
  
“then why the hell did you use _yourself_ as a lab rat!?” Sans pushed Gaster away, his eyes still stinging with fury. “if you thought so much about me, then why didn’t you care about what could happen? didn’t you care that me and pap would be-”  
  
“I had no _choice!_ ” Gaster interrupted, grabbing his son’s shoulders and shaking him. “If it hadn’t been me, then it would have been _you!_ If you knew how that machine worked, and I said ‘don’t you dare drink that vial of DT’, you would have done it with a smile on your face!”  
  
Sans glared back at him. “you don’t know that.”  
  
“Sans, I am your father.” Gaster said sternly. “I know better than anyone that you’re stubborn, defiant, and have an absolute, unwavering contempt for authority. It’s one way you really do take after me, believe it or not.”  
  
“wait, are you serious?” Despite the seriousness of the situation, Sans’ inner comedian couldn’t resist the opportunity. He smirked bitterly; “ _you?_ mr. royal scientist? mr. ‘yes your majesty, at once your majesty’?”  
  
“Believe me, there was once a time when I would have done anything - _anything_ \- to get results.” Gaster said, a sad smile crossing his face for a moment. “But tell me, Sans... if it was up to you to decide, then who would you have allowed to take the dangerous, untested, experimental drug? One of the interns? The lab technicians? Ms. Alphys, maybe? Whose neck would you have put upon the chopping block, if not your own?”  
  
Sans stuttered wordlessly.  
  
“My point exactly”, said Gaster.  
  
Sans sighed as he relented; he spent so much time down here, he was like an open book to Gaster. The old man could even see what he’d tried to hide from himself, because of _course_ he’d have done it... he’d have thrown back the contents of that vial like a shot of some godawful red liquor before anyone could even think of stopping him. There was no way in hell he’d have let his own father put his already fragile health on the line, and he couldn’t have risked someone else’s dust on his hands, either...  
  
“What’s done is done, my boy.” Gaster returned his son’s pained look, patting him on the back. “We may have discovered time travel, but as you pointed out, DT tends to stay where you put it.”  
  
Sans looked away; he couldn’t have done anything to prevent this, but the guilt was still tearing him up inside. He sniffled pathetically; he was the heart of Hotland Labs, alright. The _bleeding_ heart.  
  
“Oh come on, now… everything turned out for the better, didn’t it? I’m still here, and as for any lasting effects… well, watch this!” Gaster stood up quickly; grabbing one of the disassembled puzzle rings, he tossed it into the air, spun around, and effortlessly caught it on his fingertip. “This DT’s got me sharp as a _tack!_ I barely need to touch those blasted cabbage pills any more! No more stiff joints! No more feeling weak and cold!”  
  
Sans tried to hide his smile. “dad, you sound like an infomercial.”  
  
“Is that right? Well, could one of those snake-oil salesmen do this?” Gaster laughed; there was a small spark, and suddenly the ring was spinning on the end of his finger, continuing to spin in place even as he held his hand upside-down. “See? Blue Magic! After all these years! It’s in my bones, Sans, just like yours and your brother’s!”  
  
Okay, he was definitely smiling now, even if it was very reluctantly.  
  
“And you saw what happened earlier with your own two eye sockets! That Bravery! That Orange Magic! That warmth from within... that fire straight from the soul…” Gaster sat down and took off his glasses. Despite his enduring smile, he was starting to get a bit emotional, his voice cracking as he wiped his eyes with the back of his hand. “I haven’t felt that in _so long_ , Sans. I almost forgot how it felt to have courage like that.”  
  
“well that’s not surprising.” Sans said with a smirk; hopping off his chair and opening a portal, he handed his dad a handkerchief. “remember that one time i said there was a bug on you? bet you coulda used some bravery back then, when you yelled so loud the whole lab could hear.”  
  
“Oh come on, that’s low even for you.” Gaster laughed, shaking his head. “And if you got any lower, you’d get stepped on by a Whimsun.”  
  
“really? the ‘short guy’ jokes are coming out? and i thought you’d go for something more _high_ brow _._ ”  
  
“You started it. You forced me to stoop to your level.” Gaster chuckled, and gently pressed his forehead to his son’s, the rough equivalent of a kiss for a monster without lips. “I’m sorry, Sans.”  
  
Sans closed his eyes and sighed.  
  
“I know.” Gaster said understandingly, rubbing the top of Sans’ skull. “I don’t want to lose you, either, my boy.”  
  
A short, humorless “heh” was all that Sans could manage as a response. He felt completely exhausted, physically and emotionally, and wanted nothing more than to go to sleep and forget any of this ever happened...  
  
“Though, if I may... I just have one last thing to ask of you, before we both apologize to Papyrus for ruining Family Dinner Night.”  
  
…But the familiar sound of rattling pills was enough to wake him up immediately, and he opened his eyes to a muted, pinkish glow.  
  
“These are mine. 0.01% DT.” Gaster said. Holding up a medicine bottle with contents almost identical to his own prescription - aside from the strange color - he gave a small smile. “Effervescent, just like the Green Magic from the pharmacy. And no less unpleasant to taste, let me tell you.”  
  
Apprehension tightened like a noose around Sans’ neck as Gaster reached into his other pocket.  
  
“And these are 0.005% DT. Exactly half of my initial dose.” Taking hold of his son’s hand, he pressed the softly glowing bottle into his palm, and closed his fingers around it. “Yours. If you choose to take them.”  
  
Sans swallowed dryly; he tried to speak, but couldn’t make a sound.  
  
“Why? Well... the moment I realized you didn’t remember anything from before the Reset... that was the moment I realized, should I continue experiments with the machine, then I will do so completely alone. If no-one else remembers what has taken place, anything I do not observe and record myself will be lost. My ability to gather data, and analyse the effects on the timeline, will be severely limited.”  
  
“so you want me to… ?”  
  
“Only if _you_ want to, my boy.” Gaster said, putting his own pill bottle away, in his lab coat’s breast pocket. “As you said yourself, this stuff is experimental, largely untested, and potentially very dangerous… needless to say, if you refuse, then we need never speak of it again.” He put his hand on his son’s shoulder. “I will neither force nor coerce you to take part in this, Sans. It is entirely your decision.”  
  
Sans put the pills in his own lab coat’s pocket; somehow, he couldn’t bring himself to give them back, but he felt better not seeing them. Especially since he could have sworn the bottle felt slightly warm...  
  
“At least sleep on it, hm? Give it a few days. A week, maybe.” Gaster said, giving him one last pat on the back as he got up. “Now, enough boondoggling! This old monster still hasn’t had his eggroll, and like hell he’s letting his son scarf it down like last time. Come on then, chop-chop!”  
  
Sans followed wordlessly. Suddenly, he wasn’t hungry any more.


End file.
